Method of producing bags with opening means



2 Sheets-Sheet l R mm lt SAMUEL BERG STEIN- a INVENTOR.

S. BERGSTEIN METHOD OF PRODUCING BAGS WITH OPENING MEANS Jan. 2, 1951Filed Aug. 9, 1944 Jan. 2, 1951 s. BERGSTEIN METHOD OF PRODUCING BAGSWITH OPENING MEANS 2 Sheets-Sheet 2 Filed Aug. 9, 1944 iQE Patented Jan.2, 1951 2,536,529:- METHOD or PRODUCING BAGSWI'TH OPENING MEAN SamuelBergstein; Cincinnati, Ohio; assignor to Robert Morris Bergstein andFrank" David Bergstein, trustees Application August 9, 1944; seriaiNb.548;652'

4 Claims. 1

The inventionrelates to th'e' problem of facili tating'the removal ofthe contents of: a bag or" liner." by the user.- lts'prin'cipal objecthas to do with the provision of means for the ready removal of theliner" closure or seal, in whole or in'part;

Another object o f the invention is the attainment of the" objectivejust'mentioned, while retaining the integral nature ofthe bag or liner,so that its protective characteristics are not sacrificed; Yet anotherobject'is the provision of a; method whereby such liners" or bags maybema'de conveniently a'ndinexpensively; as hereinafter set forth,

My invention is particularly adapted for use in" connection with linedcontainers such as are shown in the Robert M. Bergstein Patents2,099,257, of November 16, 1937, and2,250,24=9, of July 22, 19 11,madeby the methods disclosed in Reissue Patent No. 20,789, of'July12,1938, and by mechanisms such as are shown in Patent 2,114,621, April19', 1938; and Patent 2,166,388, of July 18, 1939. However, theinvention is not limited to any particular types" of lined containers,but isequall suited for use'with other types or for use with separatebags as'such; as will become apparent as the description proceeds.

These and other'objects of my invention, which will'beset forthhereinaftero'r will be apparent to one skilled in the art upon reading"these specifications, I accomplish in that construction and arrangementof partsand in that procedure, ofwhich I shall novwdescribe exemplaryembodimerits.-

Referring to the drawings:

Figure 1 is a diagrammatic plan view of a section of, one form ofbagmach ne, showing the devices for performing m'y 'invention.incorporated therein;

Figure 2 shows asectioriofabag machine with an alternate form of mydevice incorporated therein.

Figure 3 is a partial sectional viewtaken along the line 3.--3 ofFigured;

Figure 4C a partial sectional view" taken along tfie=line 4l--4 ofFigure-"L Figure 5 isapartial sectional view taltenalong' theline 5-'-5ofFigureZ.

Figure 6 shows a has prepared inaccordance with my invention imposed ona carton blank as taughtin Patent 2,259,249.

t Figure is the flat; prelinedlzcarton of 'the type shown in Batent 2,250;2-49 previcu'siy'mentieneo; hutembodyingmy invention.-

Figure: 83' showercontainenzsuchiasillustrated inFi'giire-l; afterit-has been set up, filled, sealed, shipped and partially opened by theuser, that is; the top flaps have been folded back intoopenposition;exposing the sealed liner, which now must be opened.

Figures 9, 10 and 11 illustrate steps in the operation of removing thesealed-end of the-liner in accordance" withthe present invention.

Figures 1213- and 14am a" similar series otviews sho'wing the operationof opening the liner when the linenhasbeen treated as l'iereinafterexpained in connection with" Figure 2;

Briefly, in the practice of my invention; I have found that its objectsmay be attained by forming apredetermined line of weakening in the waneof a bag orliner sothat they will tear readily along" thepredeterminedline, and then" coating said weakenedline including a contiguous" area"of the bag walls with a film-forming substance capableof bonding;tightly with the said walsand capable of filling or closing perfora--tion'sin the-'weakenedline; or forming a tenacious membna'ne thereover,thus preserving the proofness of thebag walls inspiteo'f the line ofweak ening. The line or lines of weakening may be configured ashereinafter set forth. They may be continuous so as completely to definea 1 line for severance; or, in materials hard to tear at a folded edge"but readily torn after initial severance; they may merely be locatedtostar't a linepi'tean The applied film will be such thatit' willseveralong the weakened" lines in'the base w'eb'or bag'wall. The filmmaybe colored. to call attention-to theline or lines of weakening;

In Figure l is shown a section of a bag machine into which section unitlength tubes are beingdeliveredat the left'handend or the draw ing froma tubing deviceinot shown). As they enter the illustrated'ma'chinesection, the" cut-tolengthtubesare-picked up by lugs 51 on the chains56,and' so are carried in timed relation to positively drivenfrictionally surfaced: upper and lower belts 58- which continue to carrythe tubesin-timed relationship. Duringtheir course" of" traveL-the tubesmay be closed at one end! to iormbagsieithen by folding or sealing orotherwise,- as desctibedin-Patent-2.114;621 previously v mentioned.

The mechanism forperforming the present ingamma 1ower anvil roll 6tmounted r at 1!! in Figure 1. The film-forming substance is preferablyone will be driven from the machine drive in such a way that theperipheral speed of the rolls will match the speed of travel of the bagtubes as moved by the conveyor means 58.

ticularly in view of the nature of the material from which the bag tubesare made. and heavy mat rals. it is sometimes possible to weaken them bycutting them part way through their thickness. The type of weak ningwhich I prefer is provid d by making slits of short length or tinvperforations, clos l spaced in the mat rial. These sli s are largelyself-closing, so that when the subseouent coating material is applied,it will not strike through the slits to such an ext nt as eith r toadhere the walls of the bag together stron ly or to become disru tedand. therefore. no longer gas or liquid tight when the bag is forciblyopenedv as in filling.

Having been provid d with a line or lin s of In thick maining on therolls.

are thus coated with sealing substance, as in- V weakening as afor said,the bag tubes are next carried by means of the conveyor 58 to a devicewhich applies over the lines of weak ning a stripe of film-formingsubstance. An annlioation roll, 63, is shown mount d on a shaft 64iournal d on the side fra es of the machine. A lower roll 65 on a shaft66 is shown as turning in a pan or reservoir 5 of the film-formine sbstance. A doctor or blade 68 controls the thickness of the layer offilm-forming substance on the roll 65. In the ap aratus shown in Fi ure1 and detailed in Figure 4, it will be evid nt that the roll 53 picks upa la er of the coating sub tance from the lower roll 65 in the intervalsbetwe n the passage of the bag tubes 69 so that as a bag tube pa'ss sbetween the rollers. a film of the sealing substance'is applied to'it onboth sides in an area including the lin s of weakening. Such a stripe offilm-forming substance is shown 50% parafiin wax (132 M. P.) V 50%micro-crystallin wax (Petrosene B-Socony Vacuum) V 1 2% ester gum,(melting point 154) lit will be und rstood that in Figure 4 a separateapplication of the film-forming substance may be made directly to theroll 63 from a separate pan of the substance and a transfer roll.

In Figure 2 I have shown an a paratus applied to the same type ofmachine for forming lines of weakening which extend diagonally acrosscorner portions of the bag tube. This apparatus comprises. a roll Hmounted on a shaft .12

jpurnaled on the side frames of the machine.

on the roll there is a perforating device 13 extending at an angle tothe axis of the shaft. as shown. Dependinlg'upon the timing of the shaftin relation to the travel of thebag tubes, there may be one or more ofthese perforating devices.

- They operate against a lower roll 14 on a shaft similarly journaledand wide enough to serve as an anvil throughout the length of thediagonally arranged perforating device or devices. The bag tubes 69 arecarried from this mechanism by the conveyor 58 to a coating or sealingmechanism comprising in this instance upper and lower rollsl and 15 onshafts H and i8 journaled in the side frames of the machine. Each suchroll, as more clearly shown in Figure 5, has one or more raised,diagonally arranged printing surfaces, '59 or 80. These surfaces arearranged to be supplied with the sealing substance from rollers 81 and32, turning in pans 83 and 8% of the sealing substance, through transferrolls Siand 86. Doctors or blades,'8l and 83, control the thickness ofthe line of sealing substance re- The lines of perforation dicated at 89in Figure 2.

r The lines of perforation formed in the bag tubes may be made before orafter or concurrently with the formation ofeither of the end closureseams of the bag, and may be made at either or both ends of the bagtube.While I have illustrated in the drawings hereof right angle machines fortreating unit length bag tubes, the skilled worker in the art inthelight of these teachings will be readily able to adapt the mechanismsshown to the treatment of an endless length of bag tube as it is beingdelivered from a tubing device, as in Patents 2,099,257 and Re. 20,789.or diagonally of rolls may be employed for-this purpose as well as spotprinting devices appropriately shaped to apply the stripes of sealinadhesive. It is also possible to treat a strip of bag forming web so as.to provide appropriatelyrspaced lines of weakening therein and so as toseal these lines by an application. of filmforming sealing substanceprior to the tubing of the strip. In such an operation, it is possible,if desired, to cause the stripe of sealing adhesive to be located insidethe bag tube, as will be clear.

The lines of perforation and sealing films may be made across apreformed closure without impairing the closure. They may be made in bagwalls prior to closure, and when so made will not interfere with theformation of the closure or the seal thereat. perforated or weakenedprior to the formation of bagtubes and is then provided with the sealingfilms, the nature of the tubin operation becomes unimportant, andbellows-fold or intucked bag tubes may readily be made. Wherebags or bagtubes are first made andthen perforated, it is necessary to takeprecautions to insure that the sealing films cover the lines ofperforation through their length. Hence it is most con sealed at thatend prior to'the formation of lines of weakening and the coveringthereof, as described, or whether the bag tubes shall be perforated andthereafter closed and sealed.

r The machine sections shown in Figures 1 and 2 ma be caused to deliverthe ba tubes to apparatus for imposing them upon carton blanks andadhering them thereto, followed by the tubing of the carton blanks, asset forth in the patents to which reference has been made.

A bag tube 69 sealed at one end, as at 98, an having the sealed lines ofweakening It, is shown Perforating devices located axially 7 Where bagmaterial is" Figure 6 as imposed upon ai c'arton blank 's I.

This particular blank is one shown Patent 2,250,249 and istubed bybending it along score lines: intermediate the end walls: of the carton.The bag tubes, however, maybe applied to other types of carton and maybesealed at one end or open at both ends'priorto such imposition. Fi ure6' shows the application of adhesive, as at 92, so as to cause the bagor bag tube to adhere to the enclosing body walls of the carton, so thatwhen'theca-rton is squared up or erected, the bag or b'ag tube willlikewise be squared up and opened at least on one end preparatory tofilling, The lined carton 9.! is shown in knocked down form inrFigure 7.It will be erected, filled, the-bag sealed, and the carton closed,asinthe patents set forth above.

Figure 8 shows such a filled. carton after it reaches the-hands of theult mate consumer and after he has opened the flaps 93 so as to disclosethe filled bag 69. The nextstep, asindicated in Figure 9, is to pullupwardly upon the end closure seam 90 of the bag. A further upwardpulling operation, accompanied by a twisting operation, as illustratedin Figure 10, will serve to cause the upper portion of the bag to severfrom the lower portion along the weakened line formed therein which, inthis case, is a continuous peripheral line substantially. coincidingwith the upper edges of the enclosing walls of the carton. The upperportion of the bag may be entirely removed,.as shown in F gure 11,v andafter the removalofa portion of the contents 3d oi the package, it maybe reclosed by folding over the closure flaps 83;.

Where the lines of weakening have been made as described in connectionwith. Figure 2, the carton may first be opened, as shown in Figure 12,then the top of the bag raised or unfolded, shown in Figure 13. The bagmay then be torn along the lines of weaken ng 89 so as to remove acorner thereof, 95. This provides an opening in the bag through which aportion of the contents may be removed by pouring; and if the removedcorner 95 of the bag is properly proportioned, suflicient of the upperparts of the bag Walls will remain to p rmit a folding over of these bagwall portions and reclosure of the bag, as well as reclosure of thecarton, as explained above.

It will be apparent that according to my invention, the nature of thematerial to be applied to seal up the perforations or line of severancecan be adapted to the particular product to be packed within the lineror bag. In the case of lard, for example, it would be desirable to usesome greaseresistant medium so there would be no leakage or seepage ofthe fat and so that the liner would retain its integrit and provideprotection until the top is finally removed by the user, as illustrated.In the case of other products such as powders, the compound or sealingmedium over the line of perforation should serve the primary purpos ofretaining siftproofness, and in such an event, might be a material suchas paraffin wax (or a resin modified paraffin, to overcome brittleness).In certain other cases, as for example, a flaky or granular contentwithin the liner or bag, the use of any sealing medium at all may beunnecessary, in which case the perforating alone could be used,by-passing the unit which applied the sealing medium, although I preferto use the sealing medium to provide the maximum possible protection ofthe contents. A sealing medium, such as described herein, properlyapplied and bonded toi walls' ofthe bagwill, however, provide protec=tion again'st infiltration or loss of moisture, vapor and gases, wherespecial gases are employed As indicated, I. may also color the sealingmedium some distinctive" shade, such'as bright red, for example, so thatthe: lineof. tear is plainly and clearly marked, and this'is anotherfeature of my invention.

1' have indicated that my invention is adapted to use on" separatelbagsas well as bags or'liners within carton bodies, and this will now bereadily apparent from. the previous description... My opening means'isparticularly desirable and par ticularly advantageous for bags formedof'ma'terials which are difiicult to tear and which are tightly sealed,such, for example, as a bag made ofrubber hydrochloride sheeting, suchas Pliofilm laminated to "paper; In such alaminated bag, the

fused mouth is very difficult to open due to the bonding quality of thePliofilm; and the rubbery nature of the Pliofilm. liner also makes it extremelydifficultto tearsuch a bag open. By'niy invention, these problemsare entirely eliminated, and: at the same time through the use" of theproper'sealing medium to cover over the perforation or line ofseverance,the essential protective characteristics of such Pliofilm lined bags canbe fully retained, providing a protective bag or liner which can bereadily and simplyopened when desired.

Itwill. be apparent thataccording to the ad'- ,iustment of the machine,the line of severance canbe placed in any predetermined, desiredlocation, or at anydesired angle to the bag or tube itself. In Figure 9,the line of severance is placed substantially flush with the top of theouter carton but, if desired, this could be raised to the point where itwas slightly under. the sealed or. folded closure of the bag, so thatafter the sealed port on is torn there st ll remains sufficientextending material to be refolded over the surface of the contents. AsShOWn in Figure 12, the line of severance, if preferred, may be placedat an angle or on the bias, so that only a corner or a portion of theseal is removed by the user to provide a simple and effective means ofpouring, rather than removing the entire sealed area; and this is amatter of choice, depending on the nature of the product packed.

It will also be apparent from the foregoing that my invention may becarried out at various stages in the manufacture of bags or tubes.Several of them have been illustrated in the drawings; but it will bereadily apparent to those skilled in the art that, if desired, myinvention might be practiced by the incorporation of suitable devicesafter the formation of the web into a continuous tube but prior tosevering it into bag lengths.

Variations are within the sco e of my invention, and it is not intendedto limit the invention to the particular forms described, except ascovered by the claims herein. By my invention, I have provided meanswhereby flexible bags or tubes, even if made of extremely durablematerial, can be readily and easily opened by the user when desired, andI have further provided means whereby this can be achieved withoutsacrificing the inherent protective characteristics of the bag or lineritself, and. have accomplished all this with no separate manufacturingoperation or labor cost. The invention is not limited to single-plybags; and it may be applied also to coated bags, where the sealingsubstance may be the same as the coating, or a substance capable of.bonding firmly with it. Having thus described my inven- 3i tlon incertain exemplary embodiments, what! claim as new and desire to secureby Letters Patent is:

a 1. A process of forming a sealable and openable composite packagewhich comprises forming a bag tube from web materials, closingand-sealing one. end of said bag tube, forming in said bag tubetransverse lines for severance. adjacent but spaced from the closed endof said tube, coating said lines for'severance with a thermoplasticsealing subsbtance, formin a carton blank having a' series of body wallsin articulation and capable of forming a closed tube, said body wallshaving ends in alignment in said blank, otheroparts of said blankarticulated to said body walls for forming end closures thereof, anddepositing said preformed bag tube on said blank in such a way as toalign said lines for severance with the aligned ends of the body wallsof said blank, and tubing said blank about said bag tube with theinterposition of adhesive between the body walls of said blank and saidbag tube whereby to adhere said bag tube to said body. walls.

' 2. A process of forming bags or liners which includes the steps ofproviding a fiat bag tube having open ends, sealing one end of said tubetransversely by adhering the walls thereof together across said end,forming lines of perforation in opposite wall portions of said tube,said lines starting at an edge of the bag at a point adjacent but spacedfrom said transversely sealed end and extending through said sealed end,and thereafter covering said lines for severance with a thermoplasticsealing substance.

' 3. A process of forming bags or liners which comprises the steps ofproviding a flat bag tube having open ends and lines of perforation inop- 'posite wall portions of the tube, said lines starting at an edge'ofthe bag at a point adjacent but spaced from an open end thereof andextending 8 slantwise to the longitudinal axis of the bag andintersecting the said open end intermediate its ends, sealing the saidend of said tube transversely by adhering the wallsthereof togetheracross said end, and thereafter applying to said lines of perrelationand adjacent portions of the tube walls a thermoplastic sealingsubstance.

4.-A process'of making bags or liners which includes the steps ofconveying unit lengths of flexible flat bag tubes having open ends in apath of travel, sealing one end of said tubes transversely by adheringthe walls thereof together across said ends, forming lines ofperforation in opposite wall portions of said tubes, saidlines startingat an edge of the bag tubes at a point adjacent but spaced from saidtransversely sealed ends and extending through said transversely sealedend intermediate the ends thereof, and thereafter applying to said linesof perforations and adjacent portions of the tube Walls a thermoplasticsealing substance.

SAMUEL BERGSTEIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,198,278 Rosenzweig Sept. 12,1916 1,517,96 Drysdale Dec. 2, 1924 1,943,796 Hartmann Jan. 16, 19342,035,766 Potdevin et al July 6, 1937 2,129,989 Alfred Sept. 13, 19382,132,144 Blum Oct. 4, 1938 2,183,2 1? Poppe Dec. 12, 1939 2,216,527Weiss et a1. Oct; 1, 1940 2,225,288 Woehlert Dec. 1'7, 1940 r 2,293,182Vogt Aug. 18, 1942 2,382,175 1945

